The PISA is a worldwide exam administered every three years that
measures 15-year-olds in 72 countries.
About 540,000 students took the exam in 2015.

The US saw an 11-point drop in average score for math,
while remaining relatively flat in reading and science.

Business Insider

The results again raise questions about the global
competitiveness of the US educational system.

On a press call on Tuesday, Jon
Schnur, executive chairman of
America Achieves, said we need to make dramatic
progress in showing educational improvement for students.

When looking at a comparable sample of countries that
participated in the PISA exam in both 2012 (the last time
the test was administered) and 2015, the US ranking fell to 35th
from 28th in math. The US underperformed the OECD average in
math.

Scores were relatively unchanged in reading and science
compared to 2012 — down one point in each. The US performed
better than the OECD average in both subjects.

Asian countries again topped the rankings across all
subjects, and Singapore was the top performing country
across all three subjects.